Terminal bank



W. F. SMITH TERMINAL BANK June 26, 1951 2 Sheets-Sheet 1 Filed Jan. 14, 1947 INVENTOR.

WILLIAM E SMITH ATTORNEY W. F. SMITH v June 26, 1951 TERMINAL BANK 2 Sheets-Sheet 2 Filed Jan. 14, 1947 wdE INVENTOR. WILLIAM F. SMITH ATTORNEY Patented June 26, 1951 TERMINAL BANK William Francis Smith, Brooklyn, N. Y., assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application January 14, 1947, Serial No. 721,977

2 Claims. 2

The present invention relates to bank strips and especially to such strips as are used in automatic telephone systems.

Heretofore it has been proposed to make a bank strip wherein sets of transverse terminal pins are secured in the sides of a molded frame of, for example, suitable plastic insulating material, a separate thin plate of insulating material is placed across each of said sets of terminal pins and perforated at predetermined points, and longitudinal wires are electrically connected to selected terminal pins. A bank strip of this general nature is disclosed and claimed in the prior application Serial No. 525,853, filed March 10, 1944, now abandoned.

An important object of the present invention is to provide a novel and advantageous construction of bank strips containing transverse terminal pins or such terminal pins in connection with wires perpendicular thereto and constituting multiple connections for the pins.

Another important object of the invention is to provide a novel and advantageous method of making bank strips embodying features of the present invention.

Another object of the invention is to provide novel and advantageous terminal pin strips adapted for manufacture in quantity and for maintaining terminals of said pins rigidly and accurately in position.

Another object of the invention is to provide novel and advantageous bank strips comprising a plurality of terminal pins, a unitary body of insulating plastic material having opposite sides in which said terminal pins are embedded with their ends protruding, one or more panels or plate portions over the central portions of said terminal pins with openings exposing said terminal pins at desired locations and means for positioning longitudinal wires over said openings to enable electrical connections therethrough of said wires to said pins.

Another object of the present invention is to provide a terminal strip comprising terminal pins and molded thereon a complete unitary body of insulating plastic material with insulating panel parts over the pins and having openings where connections are to be made.

Another object of the invention is to provide a novel and advantageous bank strip structure wherein groups of selector pins are embedded in the sides of a unitary body of insulating material such as a suitable plastic, and thin insulating parts of said body extend over the intermediate portions of said pins, and have elongated inclined openings over the crossings of successive pins and longitudinal wires where said Wires are to be electrically connected to the pins, said body having means for positioning said longitudinal wires with respect to :said selector pins.

Another object of the invention is to provide a bank strip structure whereof the body may in a single operation be molded in complete form on the terminal pins, ready for the application of the longitudinal wires and the establishment of electrical connections thereof to the pins.

An advantageous feature of the present invention is that a plurality of bank strips can be molded on a group of wires usable for selector pins and the wires may be then out between said bank strips, thus leaving units ready for application of the longitudinal wires and connection thereof to said selector pins.

Other objects, features and advantages will appear upon consideration of the following detailed description and of the drawings, in which:

Fig. l is a top plan view of a bank strip in horizontal position, said bank strip containing transverse terminal pins, but being without wires connecting said selector pins in multiple;

Fig. 2 is a section along the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary bottom view of the left end of Fig. 1;

Fig. 4 is a section taken along the line 44 of Fig. 1;

Fig. 5 is a section taken along the line 55 of Fig. 1;

Fig. 5a is a section of a deformed part of a selector pin, said deformed section being embedded in the body of said strip;

Fig. 6 is a View similar to Fig. 1, but on a larger scale and broken away at its center, showing the longitudinal wires in position thereon and held by the plastic at the ends of the strip, said wires being electrically connected to corresponding terminal pins;

Fig. '7 is a section taken along the line 'l'! of Fig. 6; and

Fig. 8 is a section taken along the line 88 of Fig. 6.

One bank strip or terminal strip of the invention is illustrated in Fig. 1. This strip comprises a body Iii including a, frame having sides H and I2, ends l3, and connections between said sides comprising one or more panels i4 and cross pieces [5 which may be of different widths. Secured in the sides II and 12 are transversely arranged terminal pins l6 which project outwardly from said sides. Said body is made of insulating material, preferably molded plastic as for example As shown the terminal pins 16 are round in cross-section except where deformed, and are arranged parallel to each other transversely of the frame. The terminal pins may be made of any suitable conducting metal, and are preferably made of Phosphor bronze. Any desired number of these pins may be used, but as illustrated, there are thirty-two pins l8 and these (Fig. l) are arranged in groups, A, B, C and D, eight pins in each group. Inasmuch as the pins 16 project from the sides II and !2, of said bod, both ends may be used for making contact with the moving brushes 'of a selector switch or'a plurality of such switches when the device is used in automatic telephone equipment. When used for such purposes, it is desirable to have the ends of the pins in alignment, and very accurately positioned.

The bank strip thus far described would be useful in automatic telephone apparatus. However, it would have a much greater range of use if groups of the selector pins were connected in multiple with other groups and with groups of pins in similar bank strips. For such multiple connections use may be made of bare wires ll of good' conducting material such as copper, which extend longitudinally of the bank strip and are longer than the body ll]. These wires [1 are positioned over the central part of said body IE by providing deep longitudinal grooves IS in raised portions of said ends l3. These grooves i8 are arranged and spaced to position the wires parallel to each other and at even spaces across the central part of said body l0. Said panel or panel portions l4 and cross pieces [5 are integral with each other and have at the face toward said wires ll a common plane surface depressed somewhat below said sides H and i2 and ends [3. In said common plane surface within the frame are shallow grooves iSa to receive thelower parts of wires l'i. Said panel portions i l also enclose one-half of each of the selector pins between the sides H and i2.

In order to electrically connect the wires l1 to said selector pins I5 it is necessary to expose parts 'of the selector pins where electrical connections with Wires I! are to be effected. As "shown in Fig. l, the crossings of pins 16 and wires I! where electrical connections are to be made are in lines inclined with respect to the strip and in each group of eight crossings the similar groups of four are separated by one of the cross pieces i5 and therefore the lines of such crossings are offset with respect to each other. The exposure of the crossings of the wires H and the selector pins might be made through separate openings, but in view of the unitary structure of the body l0, it is much more convenient in imolding such body to have slots [9 instead of separate openings.

The wires ii are welded or otherwise electrically connected to the pins l6 where they cross, the connections being made through said slots i9. Because of the close proximity between the wires and pins a slight deformation of either or both will produce contact thereof through the slots in the panel portions M. It will be seen that i one of the wires i1 is attached to the first of the pins IS in each group A, B, C, and D, and that each of the other wires is attached to a corresponding p-in in each group. In this way the groups are connected in multiple by the longitudinal wires ll.

The wires I! should be kept stretched over the body iii and this result may be obtained while holding the wires in stretched condition by heating the thermoplastic material in areas across said ends !3 and pressing the plastic material around the wires H in said grooves l8 sufiiciently to hold them in position. In such heating and pressing of the plastic material, grooves l9a are produced in said ends I3.

It may be desirable, especially in automatic telephone apparatus, to have a number of the units of Fig. 6 connected together in a string as disclosed in said application Serial No. 525,853, filed March 10, 1944. ,Such units may be spaced apart a short distance and the wires l1 between them may be insulated in any suitable manner as by coating the same with an insulating lacquer.

The welding of the wires H to the selector pins 16 may be effected by apparatus designed for that purpose. To adapt the strip for'use in such welding apparatus, a central cross-piece I5 is provided with a slot 28 of a length substantially equal to the width of the panel portion. In the welding machine this slot permits the projection therethrough of a comb which serves to position the strip and the wires I! thereove'r. The body Hi may also be provided with transverse slots 21 in end extensions 22 to accommodate in each slot one member of cutting means for severing the wires i1. It should be understood that in use the bank strips are arranged vertically and flat against each other with the side edges in alignment.

The article illustrated in Figs. 1, -2 and 3 constitutes a selector pin strip 23 and the article illustrated in Fig. 6 is a completed bank strip 24.

The bank strips may be used singly or in strings connected by wires I! as disclosed in said application Serial No, 525,853, filed March 10', 1944. As indicated in Figs, 1 and 6, each end of each selector strip 23 and each bank strip 24 is reduced in width to provide shoulders 25 and each end of reduced width is provided at opposite edges with projections 26 of the general shape of isosceles triangles. These projections 26, are designed to fit in grooves in suitable frame members. In this way the strips are aligned.

The end extensions 22 are not found in said prior application and some changes in the stripholding frame may be made. As shown in the lower left-hand corner of either Fig. -1 or Fig. 6, the corresponding extension 22 is cut out at one side leaving a shoulder 21 extending inwardly to an edge 28. If a frame member (not shown be shaped to engage shoulder 25, projection '26, shoulder 27 and edge 28 at one cornerof the bank strip, and other frame members (not shown) be shaped to lit along a straight edge 22a of the extension 22, the first mentioned frame member would. not receive any corner of the strip but the one having the shoulder 21 and the edge 28, The construction just referred to assures proper placing of the strips in a frame.

The method of making the selector or terminal pin strip 23 illustrated in Figs. 1, 2 and 3', may be carried out in suitable apparatus of which a preferred form of molding apparatus is disclosed and claimed in my companion application Serial No, 730,969, filed February 26, .1947. The method of making the bank strip 24 of Fig. 6 from the terminal pin strip 23, may be carried out in suitable welding apparatus of which a preferred form is disclosed and claimed in mycompanion application Serial No. 727,802, filed February 11, 1947, now U. S. Patent No. 2,474,285 which issued on June 28, 1949. These methods while complete in themselves are parts of a main method of making the final bank strip 24.

In making the terminal strip 23, Wires of suitable cross-section and composition for the formation of terminal pins 16 therefrom, are advanced through a molding zone step by step with dwells therebetween and during each dwell at least one body 10 of insulating material is molded on said wires. The molded material is then moved out of the molding zone and at the next dwell another molding operation is effected. These steps are repeated until it is necessary to stop, as for example when substantially the full lengths of the wires have been used. During said dwells the wires may be out between molded bodies 10 which have been advanced a plurality of steps.

The wires from which the terminal pins 16 are out are usually supplied in close wound masses so that the wires are set in close coils of small radius. Before molding bodies It on said wires, these wires are straightened by running them through straightening apparatus. For convenience in feeding the terminal-pin wires through a molding zone or machine, they may be coiled on reels of substantial diameter. The wires may be drawn from the reels by means located between the reels and the molding zone, and the strips beyond the molding zone may be advanced by suitable means to draw newly formed terminalpin strips from the molding zone. Retrograde movement of the wires and strips may be prevented by means at the outlet side of said molding zone.

In the second part of the main method; a finished strip 23 is placed against wires I7 so that the wires are seated in the various grooves 18 in the ends l3 and grooves la in the panel 14. Then with the strip 23 in the welding zone, welding of the wires and pins may be effected at crossings thereof along said slots 19, and plastic material at the ends I3 may be softened by heating and passed down into grooves l8. The welding may be effected in a plurality of welding operations,

thus making it possible to have simultaneously H formed welds separated by substantial spaces.

After completion of the welding for a given strip, the strip and the multiple-connection wires connected thereto are drawn out of said welding zone and another strip 23 is drawn into the welding zone. During the welding for the second strip, the first-mentioned strip may be in a testing zone where all of the crossing welds are tested, preferably simultaneously. There is also a zone wherein the wires are bent to provide slack between strips. At another point along the path of travel of the strips, the wires I! are out where desired to provide individual strips or a plurality of strips. Said strips may then be assembled for mounting in terminal banks. Of course the testing of the welds may be effected after cutting off single bank strips or a plurality of connected bank strips.

It should be understood that various changes may be made and certain features used without others, without departing from the true scope and spirit of the invention.

What is claimed is:

A bank strip comprising a flat unitary frame of insulating material having a pair of spaced edges, a plurality of transverse terminal pins having portions thereof embedded in said edges and extending a predetermined distance beyond each edge, a panel insulating said plurality of terminal pins on one side of said frame, said panel being formed integral with said frame and partially surrounding said plurality of pins, a plurality of wire-receiving grooves being provided in said panel on the side opposite said terminal pins and being insulated therefrom by a portion of said panel; said panel being further provided with diagonally extending slots adapted to expose predetermined pins at every crossing of a pin by a wire receiving groove, said unitary frame havign ends formed integral with said panel and substantially flush thereto, said wire receiving grooves extending through said ends, an extension being provided on each end below the level of said wire receiving grooves for securing wires in said grooves and means formed integral with said frame for mounting said bank strip.

A bank strip as claimed in claim 1 wherein said mounting means comprises protruding portions at each corner of said frame and said frame is notched immediately adjacent to said protruding portions.

WILLIAM FRANCIS SIVHTH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 252,395 Odell Jan. 1'7, 1882 290,845 Breckenridge Dec. 25, 1883 792,391 Hanson Feb. 14, 1905 1,287,101 Reynolds Dec. 10, 1918 1,541,341 Forsberg June 9, 1925 2,019,625 OBrien Nov. 5, 1935 2,060,426 Rittenhouse Nov. 10, 1936 2,226,666 Lienzen Dec. 31, 1940 2,270,166 Hiensch Jan. 13, 1942 2,301,288 Knauf Nov. 10, 1942 2,401,451 Arey June 4, 1946 2,411,014 Warnke Nov. 12, 1946 2,424,197 Strickland July 15, 1947 FOREIGN PATENTS Number Country Date 201,092 Great Britain July 26, 1923 

